Cold production method for pearly lustre surfactant preparations

ABSTRACT

Pearlescent surfactant compositions are prepared at a temperature of from about 10° C. to about 45° C. by providing an aqueous surfactant solution and then contacting the aqueous surfactant solution with a composition comprised of a pearlizing wax and a polyol ester.

BACKGROUND OF THE INVENTION

This invention concerns generally with pearlescent preparations andespecially with cosmetics and relates to a process for the coldproduction of such preparations.

For centuries, the softly shimmering luster of pearls has held aparticular fascination for human beings. It is therefore no wonder thatmanufacturers of cosmetic preparations, endeavour to give their productsan attractive, valuable and rich appearance. The first pearlescence usedin cosmetics in the middle ages was a pearlizing paste of natural fishscales. At the beginning of the present century, it was discovered thatbismuth oxide chlorides were also capable of producing pearlescence. Bycontrast, pearlizing waxes, particularly of the glycol monofatty acidester and difatty acid ester type, are of importance in moderncosmetics, being used mainly for the production of pearlescence in hairshampoos and shower gels. An overview of modern pearlizing formulationswas published by A. Ansmann and R. Kawa in Parf. Kosm., 75, 578 (1994).

Various formulations capable of providing surface-active products withthe required pearlescence are known from the prior art. For example,German patent applications DE 38 43 572 A1 and DE 41 03 551 A1 (Henkel)describe pearlizing concentrates in the form of free-flowing aqueousdispersions containing 15 to 40% by weight of pearlizing components, 5to 55% by weight of emulsifiers and 0.1 to 5% by weight or 15 to 40% byweight of polyols. The pearlizing waxes are acylated polyalkyleneglycols, monoalkanolamides, linear saturated fatty acids orketosulfones. European patents EP 0 181 773 B1 and EP 0 285 389 B1(Procter & Gamble) describe shampoo compositions containing surfactants,non-volatile silicones and pearlizing waxes. European patent applicationEP 0 205 922 A2 (Henkel) relates to free-flowing pearlizing concentratescontaining 5 to 15% by weight of acylated polyglycols, 1 to 6% by weightof fatty acid monoethanolamides and 1 to 5% by weight of nonionicemulsifiers. According to the teaching of European patent EP 0 569 843B1 (Hoechst), nonionic, free-flowing pearlizing dispersions can also beobtained by preparing mixtures of 5 to 30% by weight of acylatedpolyglycols and 0.1 to 20% by weight of selected nonionic surfactants.In addition, European patent application EP 0 581 193 A2 (Hoechst)describes free-flowing, preservative-free pearlizing dispersionscontaining acylated polyglycol ethers, betaines, anionic surfactants andglycerol. Finally, European patent application EP 0 684 302 A1 (Th.Goldschmidt) relates to the use of polyglycerol esters ascrystallization aids for the production of pearlizing concentrates.

Commercially available pearlizing waxes have melting points above 80° C.and, accordingly, cannot be incorporated cold into water-basedformulations. Because of this, the expert has to use a hot process inwhich the waxes are melted and allowed to crystallize out slowly in theformulation, the particle fineness of the crystals and hence thebrilliance of the pearlescence being a function of the cooling rate.Accordingly, it is immediately clear that hot processes aretime-consuming and energy-intensive so that there is a need for a morefavorable alterative. In general, therefore, the expert looks toso-called pearlizing concentrates which are more or less concentratedsurfactant preparations which already contain the pearlizing waxes infine-particle, i.e. pearlescent, form and which are stabilized byemulsifiers. Although pearlizing concentrates of the type in questioncan be further processed cold, the actual problem is not solved in thisway and is merely passed onto to the manufacturer of these intermediateproducts because the concentrates in turn can of course only be obtainedby a hot process.

Accordingly, the problem addressed by the present invention was toprovide a process for the cold incorporation of pearlizing waxes insurfactant preparations—whether intermediate products, such aspearlizing concentrates for example, or end formulations, such asshampoos for example. At the same time, neither the brilliance of thepearlescence nor the stability of the formulations would be adverselyaffected by the cold process.

DESCRIPTION OF THE INVENTION

The present invention relates to a process for the cold production ofpearlizing surfactant preparations in which aqueous surfactant solutionsare initially introduced and mixtures of pearlizing waxes and polyolesters are stirred in at temperatures of 10 to 45° C. and preferably 15to 25° C.

It has surprisingly been found that even the addition of smallquantities of polyol esters reduces the melting point of pearlizingwaxes to such an extent that they may readily be incorporated cold (10to 25° C.) in surfactant-containing formulations. Irrespective ofwhether the preparations are intermediate products (for examplepearlizing concentrates) or end formulations for the consumer (forexample shampoos, dishwashing detergents), they have a brilliantpearlescence, are stable in storage and even allow the incorporation ofdifficult ingredients, such as silicone oils for example. The inventionincludes the observation that not only pearlescent preparations, butalso white, densely opaque preparations can be produced in this way,depending on the type of wax and emulsifier used.

Surfactant-containing Preparations

As already explained, the surfactant-containing preparations may be bothintermediate products and pearlizing concentrates or end formulationsfor the consumer, such as hair shampoos or dishwashing detergents forexample. The surfactants present in the preparations may be anionic,nonionic, cationic and/or amphoteric or zwitterionic surfactants whichmay make up from 1 to 35% by weight, preferably 5 to 15 or 15 to 40% byweight and more preferably 25 to 35% by weight of the preparation,depending on whether it is a concentrate or a dilute solution.

Typical examples of anionic surfactants are soaps, alkylbenzenesulfonates, alkane sulfonates, olefin sulfonates, alkyl ethersulfonates, glycerol ether sulfonates, a-methyl ester sulfonates,sulfofatty acids, alkyl sulfates, fatty alcohol ether sulfates, glycerolether sulfates, fatty acid ether sulfates, hydroxy mixed ether sulfates,monoglyceride (ether) sulfates, fatty acid amide (ether) sulfates, mono-and dialkyl sulfosuccinates, mono- and dialkyl sulfosuccinamates,sulfotriglycerides, amide soaps, ether carboxylic acids and saltsthereof, fatty acid isethionates, fatty acid sarcosinates, fatty acidtaurides, N-acyl amino acids such as, for example, acyl lactylates, acyltartrates, acyl glutamates and acyl aspartates, alkyl oligoglucosidesulfates, protein fatty acid condensates (especially wheat-basedvegetable products) and alkyl (ether)phosphates. If the anionicsurfactants contain polyglycol ether chains, the polyglycol ether chainsmay have a conventional homolog distribution, although they preferablyhave a narrow homolog distribution.

Typical examples of nonionic surfactants are fatty alcohol polyglycolethers, alkylphenol polyglycol ethers, fatty acid polyglycol esters,fatty acid amide polyglycol ethers, fatty amine polyglycol ethers,alkoxylated triglycerides, mixed ethers and mixed formals, hydroxy mixedethers, optionally partially oxidized alk(en)yl oligoglycosides orglucuronic acid derivatives, fatty acid-N-alkyl glucamides, proteinhydrolyzates (more particularly wheat-based vegetable products), polyolfatty acid esters, sugar esters, sorbitan esters, polysorbates and amineoxides. If the nonionic surfactants contain polyglycol ether chains, thepolyglycol ether chains may have a conventional homolog distribution,although they preferably have a narrow homolog distribution.

Typical examples of cationic surfactants are quatemary ammoniumcompounds, for example dimethyl distearyl ammonium chloride, andesterquats, more particularly quatemized fatty acid trialkanolamineester salts.

Typical examples of amphoteric or zwitterionic surfactants arealkylbetaines, alkylamidobetaines, aminopropionates, aminoglycinates,imidazolinium betaines and sulfobetaines.

The surfactants mentioned are all known compounds. Information on theirstructure and production can be found in relevant synoptic works, cf.for example J. Falbe (ed.), “Surfactants in Consumer Products”, SpringerVerlag, Berlin, 1987, pages 54 to 124 or J. Falbe (ed.), “Katalysatoren,Tenside und Mineralöladditive (Catalysts, Surfactants and Mineral OilAdditives)”, Thieme Verlag, Stuttgart, 1978, pages 123-217. Thesurfactant-containing preparations may contain other typical auxiliariesand additives such as, for example, oil components, superfatting agents,consistency factors, thickeners, polymers, silicone compounds, fats,waxes, stabilizers, biogenic agents, deodorizers, antiperspirants,anti-dandruff agents, film formers, swelling agents, UV protectionfactors, antioxidants, hydrotropes, preservatives, insect repellents,self-tanning agents, solubilizers, perfume oils, dyes and the like.

Pearlizing Waxes

Suitable pearlizing waxes are, for example, alkylene glycol esters,fatty acid alkanolamides, partial glycerides, esters of polybasic,optionally hydroxysubstituted carboxylic acids, fatty alcohols, fattyacids, fatty ketones, fatty aldehydes, fatty ethers, fatty carbonates,ring opening products of olefin epoxides and mixtures thereof.

The alkylene glycol esters which form component (a1) are normallymonoesters and/or diesters of alkylene glycols corresponding to formula(III):

R⁵CO(OA)_(n)OR⁶  (III)

in which R⁵CO is a linear or branched, saturated or unsaturated acylgroup containing 6 to 22 carbon atoms, R⁶ is hydrogen or has the samemeaning as R⁵CO and A is a linear or branched alkylene group containing2 to 4 carbon atoms and n is a number of 1 to 5. Typical examples aremonoesters and/or diesters of ethylene glycol, propylene glycol,diethylene glycol, dipropylene glycol, triethylene glycol ortetraethylene glycol with fatty acids containing 6 to 22 and preferably12 to 18 carbon atoms, such as caproic acid, caprylic acid,2-ethylhexanoic acid, capric acid, lauric acid, isotridecanoic acid,myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearicacid, oleic acid, elaidic acid, petroselic acid, linoleic acid,linolenic acid, elaeostearic acid, arachic acid, gadoleic acid, behenicacid and erucic acid and technical mixtures thereof. Ethylene glycolmonostearate and/or distearate is/are particularly preferred.

Fatty acid alkanolamides suitable as pearlizing waxes of group (a2)correspond to formula (IV):

R⁷CO—NR⁸—B—OH  (IV)

in which R⁷CO is a linear or branched, saturated or unsaturated acylgroup containing 6 to 22 carbon atoms, R⁸ is hydrogen or an optionallyhydroxy-substituted alkyl group containing 1 to 4 carbon atoms and B isa linear or branched alkylene group containing 1 to 4 carbon atoms.Typical examples are condensation products of ethanolamine, methylethanol-amine, diethanolamine, propanolamine, methyl propanolamine anddipropanolamine and mixtures thereof with caproic acid, caprylic acid,2-ethylhexanoic acid, capric acid, lauric acid, isotridecanoic acid,myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearicacid, oleic acid, elaidic acid, petroselic acid, linoleic acid,linolenic acid, elaeostearic acid, arachic acid, gadoleic acid, behenicacid and erucic acid and technical mixtures thereof. Stearic acidethanolamide is particularly preferred.

Partial glycerides which have pearlizing properties and which formcomponent (a3) are monoesters and/or diesters of glycerol with linear,saturated fatty acids, i.e. for example caproic acid, caprylic acid,capric acid, lauric acid, myristic acid, palmitic acid, palmitoleicacid, stearic acid, behenic acid and technical mixtures thereof. Theycorrespond to formula

in which R⁹CO is a linear, saturated acyl group containing 6 to 22carbon atoms, R¹⁰ and R¹¹ independently of one another representhydrogen or have the same meaning as R⁹CO, x, y and z together stand for0 or for a number of 1 to 30 and X is an alkali or alkaline earth metal,with the proviso that at least one of the two substituents R¹⁰ and R₁₁is hydrogen. Typical examples are lauric acid monoglyceride, lauric aciddiglyceride, coconut fatty acid monoglyceride, coconut fatty acidtriglyceride, palmitic acid monoglyceride, palmitic acid triglyceride,stearic acid monoglyceride, stearic acid diglyceride, tallow fatty acidmonoglyceride, tallow fatty acid diglyceride, behenic acidmonoglyceride, behenic acid diglyceride and technical mixtures thereofwhich may still contain small quantities of triglyceride from theproduction process.

Other suitable pearlizing waxes which form component (a4) are esters ofpolybasic, optionally hydroxysubstituted carboxylic acids with fattyalcohols containing 6 to 22 carbon atoms. Metal salts, more particularlyalkali metal slats, of monoesters of dicarboxylic acids or of mono-and/or diesters of tricarboxylic acids are also suitable. In oneparticular embodiment of the invention, esters of polybasic carboxylicacids, preferably hydroxycarboxylic acids, with partial esters ofpolyols and metal salts of the corresponding semiesters may also be usedas component (a4). The acid component of these esters may be selected,for example, from malonic acid, maleic acid, fumaric acid, adipic acid,sebacic acid, azelaic acid, dodecanedioic acid, phthalic acid,isophthalic acid and, more particularly, succinic acid and also malicacid, citric acid and, more particularly, tartaric acid and mixturesthereof. The fatty alcohols contain 6 to 22, preferably 12 to 18 andmore preferably 16 to 18 carbon atoms in the alkyl chain. Typicalexamples are caproic alcohol, caprylic alcohol, 2-ethylhexyl alcohol,capric alcohol, lauryl alcohol, isotridecyl alcohol, myristyl alcohol,cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl alcohol,oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, linolyl alcohol,linolenyl alcohol, elaeostearyl alcohol, arachyl alcohol, gadoleylalcohol, behenyl alcohol, erucyl alcohol and brassidyl alcohol andtechnical mixtures thereof. The esters may be present as full or partialesters; monoesters and, above all, diesters of carboxylic orhydroxycarboxylic acids preferably being used. Typical examples aresuccinic acid mono- and dilauryl ester, succinic acid mono- anddicetearyl ester, succinic acid mono- and distearyl ester, tartaric acidmono- and dilauryl ester, tartaric acid mono- and dicocoalkyl ester,tartaric acid mono- and dicetearyl ester, citric acid mono-, di- andtrilauryl ester, citric acid mono-, di- and tricocoalkyl ester andcitric acid mono-, di- and tricetearyl ester and metal salts thereof,preferably alkali metal salts.

Another group of pearlizing waxes (a5) are fatty alcohols and/or fattyacids corresponding to formula (VI):

R¹²OH  (VI)

in which R¹² is a linear optionally hydroxysubstituted alkyl groupand/or acyl group containing 16 to 48 and preferably 18 to 36 carbonatoms. Typical examples of suitable alcohols are cetearyl alcohol,hydroxystearyl alcohol, behenyl alcohol and oxidation products oflong-chain paraffins. Examples of acids are stearic acid, hydroxystearicacid and, more particularly behenic acid in a purity of preferably morethan 90% by weight. Fatty ketones suitable as component (a6) preferablycorrespond to formula (VII):

R¹³-O-R¹  (VII)

in which R¹³ and R¹⁴ independently of one another represent alkyl and/oralkenyl groups containing 1 to 22 carbon atoms, with the proviso thatthey contain a total of at least 24 and preferably 32 to 48 carbonatoms. The ketones may be prepared by known methods, for example bypyrolysis of the corresponding fatty acid magnesium salts. The ketonesmay be symmetrical or non-symmetrical, although the two substituents R¹³and R¹⁴ preferably differ from one another by only one carbon atom andare derived from fatty acids containing 16 to 22 carbon atoms. Stearoneis distinguished by particularly advantageous pearlizing properties.

Fatty aldehydes (a7) suitable as pearlizing waxes preferably correspondto formula (VIII):

R¹⁵COH  (VII)

in which R¹⁵CO is a linear or branched acyl group containing 24 to 48and preferably 28 to 38 carbon atoms.

Other suitable pearlizing waxes (a8) are fatty ethers corresponding toformula (IX):

 R¹⁶-O-R¹⁷  (IX)

in which R¹⁶ and R¹⁷ independently of one another represent alkyl and/oralkenyl groups containing 1 to 22 carbon atoms, with the proviso thatthey contain a total of at least 24 and preferably 32 to 48 carbonatoms. Fatty ethers of the type mentioned are normally prepared byacidic condensation of the corresponding fatty alcohols. Fatty etherswith particularly advantageous pearlizing properties are obtained bycondensation of fatty alcohols containing 16 to 22 carbon atoms such as,for example, cetyl alcohol, cetearyl alcohol, stearyl alcohol,isostearyl alcohol, oleyl alcohol, behenyl alcohol and/or erucylalcohol.

Other suitable pearlizing waxes (a9) are fatty carbonates correspondingto formula (X):

R¹⁸OCO-OR¹⁹  (X)

in which R¹⁸ and R¹⁹ independently of one another are alkyl and/oralkenyl groups containing 1 to 22 carbon atoms, with the proviso thatthey contain a total of at least 24 and preferably 32 to 48 carbonatoms. The substances are obtained by transesterifying dimethyl ordiethyl carbonate, for example, with the corresponding fatty alcohols bymethods known per se. Accordingly, the fatty carbonates may besymmetrical or non-symmetrical. However, carbonates in which R¹⁸ and R¹⁹are the same and represent alkyl groups containing 16 to 22 carbon atomsare preferably used. Transesterification products of dimethyl or diethylcarbonate with cetyl alcohol, cetearyl alcohol, stearyl alcohol,isostearyl alcohol, oleyl alcohol, behenyl alcohol and/or erucyl alcoholin the form of their monoesters and diesters and technical mixturesthereof are particularly preferred.

Finally, the ring-opening products which form group (a10) are knownsubstances which are normally obtained by acid-catalyzed reaction ofterminal or internal olefin epoxides with aliphatic alcohols. Thereaction products preferably correspond to formula (XI):

in which R²⁰ and R²¹ represent hydrogen or an alkyl group containing 10to 20 carbon atoms, with the proviso that the sum total of carbon atomsof R²⁰ and R²¹ is between 10 and 20 and R²² is an alkyl and/or alkenylgroup containing 12 to 22 and/or the residue of a polyol containing 2 to15 carbon atoms and 2 to 10 hydroxyl groups. Typical examples arering-opening products of x-dodecene epoxide, x-hexadecene epoxide,a-octadecene epoxide, a-eicosene epoxide, a-docosene epoxide, i-dodeceneepoxide, i-hexadecene epoxide, i-octadecene epoxide, i-eicosene epoxideand/or i-docosene epoxide with lauryl alcohol, cocofatty alcohol,myristyl alcohol, cetyl alcohol, cetearyl alcohol, stearyl alcohol,isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinylalcohol, linolyl alcohol, linolenyl alcohol, behenyl alcohol and/orerucyl alcohol. Ring opening products of hexa- and/or octadeceneepoxides with fatty alcohols containing 16 to 18 carbon atoms arepreferably used. If polyols are used instead of the fatty alcohols forthe ring opening reaction, they are selected for example from thefollowing substances: glycerol; alkylene glycols such as, for example,ethylene glycol, diethylene glycol, propylene glycol, butylene glycol,hexylene glycol and polyethylene glycols with an average molecularweight of 100 to 1,000 dalton; technical oligoglycerol mixtures with adegree of self-condensation of 1.5 to 10 such as, for example, technicaldiglycerol mixtures with a diglycerol content of 40 to 50% by weight;methylol compounds such as, in particular, trimethylol ethane,trimethylol propane, trimethylol butane, pentaerythritol anddipentaerythritol; lower alkyl glucosides, more particularly thosecontaining 1 to 8 carbon atoms in the alkyl chain such as, for example,methyl and butyl glucoside; sugar alcohols containing 5 to 12 carbonatoms such as, for example, sorbitol or mannitol, sugars containing 5 to12 carbon atoms such as, for example, glucose or sucrose; amino sugarssuch as, for example, glucamine. If G. pearlizing concentrates are to beproduced by the process according to the invention, the pearlizing waxesnormally make up from 5 to 45%, preferably from 10 to 45 and morepreferably from 25 to 35% by weight of the preparations. In the case ofend formulations, the pearlescence content is of course far lower and istypically from 0.5 to 3% by weight and preferably from 1 to 2% byweight.

Polyol Esters

Polyol esters which are used in accordance with the invention to lowerthe melting point of the pearlizing waxes may be selected from thefollowing groups of compounds:

partial esters of glycerol and/or sorbitan with unsaturated, linear orsaturated, branched fatty acids containing 12 to 22 carbon atoms and/orhydroxycarboxylic acids containing 3 to 18 carbon atoms and adductsthereof with 1 to 30 mol of ethylene oxide;

partial esters of polyglycerol (average degree of self-condensation 2 to8), polyethylene glycol (molecular weight 400 to 5000),trimethylolpropane, pentaerythritol, sugar alcohols (for examplesorbitol), alkyl glucosides (for example methyl glucoside, butylglucoside, lauryl glucoside) and polyglucosides (for example cellulose)with saturated and/or unsaturated, linear or branched fatty acidscontaining 12 to 22 carbon atoms and/or hydroxycarboxylic acidscontaining 3 to 18 carbon atoms and adducts thereof with 1 to 30 molethylene oxide;

mixed esters of pentaerythritol, fatty acids, citric acid and fattyalcohol according to DE 11 65 574 PS and/or mixed esters of fatty acidscontaining 6 to 22 carbon atoms, methyl glucose and polyols, preferablyglycerol or polyglycerol.

Typical examples of suitable partial glycerides are hydroxystearic acidmonoglyceride, hydroxystearic acid diglyceride, isostearic acidmonoglyceride, isostearic acid diglyceride, oleic acid monoglyceride,oleic acid diglyceride, ricinoleic acid monoglyceride, ricinoleic aciddiglyceride, linoleic acid monoglyceride, linoleic acid diglyceride,linolenic acid monoglyceride, linolenic acid diglyceride, erucic acidmonoglyceride, erucic acid diglyceride, tartaric acid monoglyceride,tartaric acid diglyceride, citric acid monoglyceride, citric aciddiglyceride, malic acid monoglyceride, malic acid diglyceride andtechnical mixtures thereof which may still contain small quantities oftriglyceride from the production process. Addition products of 1 to 30

and preferably 5 to 10 mol ethylene oxide with the partial glyceridesmentioned are also suitable.

Suitable sorbitan esters are sorbitan monoisostearate, sorbitansesquiisostearate, sorbitan diisostearate, sorbitan triisostearate,sorbitan monooleate, sorbitan sesquioleate, sorbitan dioleate, sorbitantrioleate, sorbitan monoerucate, sorbitan sesquierucate, sorbitandierucate, sorbitan trierucate, sorbitan monoricinoleate, sorbitansesquiricinoleate, sorbitan diricinoleate, sorbitan triricinoleate,sorbitan monohydroxystearate, sorbitan sesquihydroxystearate, sorbitandihydroxystearate, sorbitan trihydroxystearate, sorbitan monotartrate,sorbitan sesquitartrate, sorbitan ditartrate, sorbitan tritartrate,sorbitan monocitrate, sorbitan sesquicitrate, sorbitan dicitrate,sorbitan tricitrate, sorbitan monomaleate, sorbitan sesquimaleate,sorbitan dimaleate, sorbitan trimaleate and technical mixtures thereof.Addition products of 1 to 30 and preferably 5 to 10 mol ethylene oxideonto the sorbitan esters mentioned are also suitable.

Typical examples of suitable polyglycerol esters are Polyglyceryl-2Dipolyhydroxystearate (Dehymuls® PGPH), Polyglycerin-3-Diisostearate(Lameform® TGI), Polyglyceryl4 Isostearate (Isolan® GI 34),Polyglyceryl-3 Oleate, Diisostearoyl Polyglyceryl-3 Diisostearate(Isolan® PDI), Poly-glyceryl-3 Methylglucose Distearate (Tego Care®450), Polyglyceryl-3 Beeswax (Cera Bellina®), Polyglyceryl4 Caprate(Polyglycerol Caprate T2010/90), Polyglyceryl-3 Cetyl Ether (Chimexane®NL), Polyglyceryl-3 Distearate (Cremophor® GS 32) and PolyglycerylPolyricinoleate (Admul® WOL 1403), Polyglyceryl Dimerate Isostearate andmixtures thereof.

Examples of other suitable polyolesters are the mono-, di- and triestersof trimethylol propane or pentaerythritol with lauric acid, cocofattyacid, tallow fatty acid, palmitic acid, stearic acid, oleic acid,behenic acid and the like optionally reacted with 1 to 30 mol ethyleneoxide.

If pearlizing concentrates are to be produced by the process accordingto the invention, the polyolesters typically make up from 0.5 to 15% byweight, preferably from 1 to 10% by weight and more preferably from 5 to8% by weight of the preparations. In the case of end formulations, thepolyol ester content is of course far lower and is typically from 0.1 to1% by weight and preferably about 0.5% by weight. As a rule, the polyolester content, based on the quantity of pearlizing wax, is typicallyfrom 1 to 15% by weight and preferably from 5 to 10% by weight.

Emulsifiers

As already mentioned, the surfactant-containing preparations maybasically contain any type of surfactant, the choice of surfactant beingdetermined solely by the desired performance profile for the particularend use. In a preferred embodiment of the invention, however, thesurface-containing preparations are pearlizing concentrates, i.e.intermediate products. In this case, the choice of the surfactantcomponent is more critical because the requirement profile consistsprimarily in permanently stabilizing large amounts of the pearlizing waxand at the same time keeping the viscosity of the preparations so lowthat they can still be readily pumped and dosed. This purpose may beserved, for example, by nonionic surfactants from at least one of thefollowing groups:

products of the addition of 2 to 30 mol ethylene oxide and/or 0 to 5 molpropylene oxide onto linear fatty alcohols containing 8 to 22 carbonatoms, onto fatty acids containing 12 to 22 carbon atoms, ontoalkylphenols containing 8 to 15 carbon atoms in the alkyl group and ontoalkylamines containing 8 to 22 carbon atoms in the alkyl group;

alkyl mono- and oligoglycosides containing 8 to 22 carbon atoms in thealkyl group and ethoxylated analogs thereof;

products of the additon of 1 to 15 mol ethylene oxide onto castor oiland/or hydrogenated castor oil;

products of the addition of 15 to 60 mol ethylene oxide onto castor oiland/or hydrogenated castor oil;

mono-, di- and trialkyl phosphates and mono-, di- and/or tri-PEG-alkylphosphates and salts thereof;

wool wax alcohols;

polysiloxane/polyalkyl polyether copolymers and correspondingderivatives;

polyalkylene glycols and

glycerol carbonate.

The addition products of ethylene oxide and/or propylene oxide ontofatty alcohols, fatty acids, alkylphenols or onto castor oil are knowncommercially available products. They are homolog mixtures of which theaverage degree of alkoxylation corresponds to the ratio between thequantities of ethylene oxide and/or propylene oxide and substrate withwhich the addition reaction is carried out. C_(12/18) fatty acidmonoesters and diesters of addition products of ethylene oxide ontoglycerol are known as refatting agents for cosmetic preparations from DE20 24 051 PS. C_(8/18) alkyl mono- and oligoglycosides, their productionand their use are known from the prior art. They are produced inparticular by reacting glucose or oligosaccharides with primary C₈₋₁₈alcohols. So far as the glycoside unit is concerned, both monoglycosidesin which a cyclic sugar unit is attached to the fatty alcohol by aglycoside bond and oligomeric glycosides with a degree ofoligomerization of preferably up to about 8 are suitable. The degree ofoligomerization is a statistical mean value on which the homologdistribution typical of such technical products is based.

In addition, zwitterionic surfactants may be used as emulsifiers.Zwitterionic surfactants are surface-active compounds which contain atleast one quaternary ammonium group and at least one carboxylate and onesulfonate group in the molecule. Particularly suitable zwitterionicsurfactants are the so-called betaines, such as the N-alkyl-N,N-dimethylammonium glycinates, for example cocoalkyl dimethyl ammonium glycinate,N-acylaminopropyl-N,N-dimethyl ammonium glycinates, for examplecocoacylaminopropyl dimethyl ammonium glycinate, and2-alkyl-3-carboxymethyl-3-hydroxyethyl imidazolines containing 8 to 18carbon atoms in the alkyl or acyl group and cocoacylaminoethylhydroxyethyl carboxymethyl glycinate. The fatty acid amide derivativeknown under the CTFA name of Cocoamidopropyl Betaine is particularlypreferred. Ampholytic surfactants are also suitable emulsifiers.Ampholytic surfactants are surface-active compounds which, in additionto a C_(8/18) alkyl or acyl group, contain at least one free amino groupand at least one —COOH—or —SO₃H—group in the molecule and which arecapable of forming inner salts. Examples of suitable ampholyticsurfactants are N-alkyl glycines, N-alkyl propionic acids,N-alkylaminobutyric acids, N-alkyliminodipropionic acids,N-hydroxyethyl-N-alkylamidopropyl glycines, N-alkyl taurines, N-alkylsarcosines, 2-alkylaminopropionic acids and alkylaminoacetic acidscontaining around 8 to 18 carbon atoms in the alkyl group. Particularlypreferred ampholytic surfactants are N-coco-alkylaminopropionate,cocoacylaminoethyl aminopropionate and C_(2/18) acyl sarcosine.

Finally, cationic surfactants are also suitable emulsifiers, those ofthe esterquat type, preferably methyl-quaternized difatty acidtriethanolamine ester salts, being particularly preferred.

Polyols

If highly concentrated pearlizing concentrates are to be produced, itcan be of advantage to use polyols to lower the viscosity. Suitablepolyols preferably contain 2 to 15 carbon atoms and at least twohydroxyl groups. The polyols may contain other functional groups, moreespecially amino groups, or may be modified with nitrogen. Typicalexamples are

glycerol;

alkylene glycols such as, for example, ethylene glycol, diethyleneglycol, propylene glycol, butylene glycol, hexylene glycol andpolyethylene glycols with an average molecular weight of 100 to 1000dalton;

technical oligoglycerol mixtures with a degree of self-condensation of1.5 to 10 such as, for example, technical diglycerol mixtures with adiglycerol content of 40 to 50% by weight;

methylol compounds such as, in particular, trimethylol ethane,trimethylol propane, trimethylol butane, pentaerythritol anddipentaerythritol;

lower alkyl glucosides, particularly those containing 1 to 8 carbonatoms in the alkyl group, for example methyl and butyl glucoside;

sugar alcohols containing 5 to 12 carbon atoms, for example sorbitol ormannitol;

sugars containing 5 to 12 carbon atoms, for example glucose or sucrose;

amino sugars, for example glucamine;

dialcoholamines, such as diethanolamine or 2-aminopropane-1,3-diol.

The polyols are used in quantities of typically 0.1 to 15 and preferably0.5 to 5% by weight, based on the surfactant-containing preparations. Iflarger quantities of polyol, preferably glycerol or ethylene glycol, areused, the concentrates are simultaneously stabilized against microbialinfestation.

Production Process

The surfactant-containing preparations are normally produced byinitially introducing an aqueous surfactant or emulsifier mixture,optionally together with other auxiliaries and additives, at 10 to 25°C., introducing the mixture of pearlizing wax and polyol ester at thattemperature and homogenizing the whole followed by crystallization. Inan alternative method of production, a concentrated aqueous (anionic)surfactant paste may be initially introduced, the mixture of pearlizingwax and polyolester stirred in cold and the mixture subsequently dilutedwith more water to the required concentration or the mixing step may becarried out in the presence of polymeric hydrophilic thickeners such as,for example, hydroxypropyl celluloses, xanthan gum or polymers of theCarbomer type. Finally, the mixture of pearlizing wax and polyol estermay also be dissolved or dispersed in part of the aqueous surfactantsolution and then mixed with the main quantity of the preparation.

Examples

The melting-point-lowering effect of adding polyol esters tocommercially available pearlizing waxes is illustrated in Table 1. Thepure waxes and mixtures of 90% by weight wax and 10% by weight polyolester were compared. Shampoos with the following composition were thenprepared: 12 g cocofatty alcohol+2EO sulfate sodium salt, 1.5 g dimethylpolysiloxane, 3 g cocoalkyl glucoside and 1.5 g of an esterquat (waterto 100% by weight). The preparations were (a) heated to 90° C. and,after addition of 1 g of pearlizing waxes C1 to C4, were cooled toambient temperature over 1 hour or (b) mixtures 1 to 4 were added inquantities of 1 g at 20° C. The particle fineness of the pearlescentcrystals in the hair shampoos was visually evaluated under a microscopeon a scale of 1=very fine crystals to 5=coarse crystals. Pearlescencewas also evaluated on a scale of 1=sparkling to 5=dull. The results arealso set out in Table 1.

TABLE 1 Melting point reduction of pearlizing waxes and performance inshampoos (quantities as % by weight) Composition/performance C1 C2 C3 C41 2 2 4 Ethyleneglycol Distearate 100 — — — 90 — — — Glyceryl Stearate —100 — — — 90 Distearyl Ether — — 100 — — — 90 Distearyl Malate — — — 100— — — 90 Sorbitan Oleate — — — — 10 — — — PEG-3 TrimethylolpropaneDistearate — — — — — 10 — — Polyglyceryl-2-Dipolyhydroxystearate — — — —— — 10 — Polyglycerin-3-Diisostearate — — — — — — — 10 Melting point [°C.] 60 58 60 60 45 45 44 44 Pearlescence in the formulation Brilliance1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Particle fineness 1.0 1.0 1.0 1.0 1.01.0 1.0 1.0

What is claimed is:
 1. A process for the cold production of a pearlizingsurfactant composition comprising the steps of: (1) providing an aqueoussurfactant solution; (2) contacting the aqueous surfactant solution witha composition comprised of a pearlizing wax and a polyol ester at atemperature of from about 10° C. to about 45° C.
 2. The process of claim1 wherein the surfactant is selected from the group consisting of ananionic surfactant, a nonionic surfactant, a cationic surfactant, anamphoteric surfactant, and a zwitterionic surfactant.
 3. The process ofclaim 1 wherein the concentration of the surfactant in the aqueoussurfactant solution is from about 1% to about 35% by weight.
 4. Theprocess of claim 3 wherein the concentration of the surfactant is fromabout 5% to about 15% by weight.
 5. The process of claim 3 wherein theconcentration of the surfactant is from about 25% to about 35% byweight.
 6. The process of claim 1 wherein the pearlizing wax is selectedfrom the group consisting of an alkylene glycol ether, a fatty acidalkanolamide, a partial glyceride, an ester of a polybasic carboxylicacid, an ester of a hydroxy-susbstituted polybasic carboxylic acid, afatty alcohol, a fatty acid, a fatty ketone, a fatty aldehyde, a fattyether, a fatty carbonate, and a ring opening product of an olefinepoxide.
 7. The process of claim 1 wherein the polyol ester is selectedfrom the group consisting of a partial ester of glycerol or sorbitanwherein the acid portion of the ester is a saturated or unsaturated,linear or branched fatty acid having from about 12 to about 22 carbonatoms or a hydroxy-substituted carboxylic acid having from about 3 toabout 18 carbon atoms and adducts thereof having from 1 to about 30moles of ethylene oxide; a partial ester of polyglycerol, polyethyleneglycol, trimethylol propane, pentaerythritol, an alkyl polyglucosidewherein the acid portion of the ester is a saturated or unsaturated,linear or branched fatty acid having from about 12 to about 22 carbonatoms or a hydroxy-substituted carboxylic acid having from about 3 toabout 18 carbon atoms and adducts thereof having from 1 to about 30moles of ethylene oxide; mixed esters of pentaerythritol, fatty alcoholsand fatty acids and citric acid; mixed esters of fatty acids having fromabout 6 to about 22 carbon atoms; a mixture of methyl glucose and apolyol.
 8. The process of claim 1 wherein the polyolester is present inan amount of from about 0.1% to about 15% by weight.
 9. The process ofclaim 1 wherein when the surfactant concentration is from about 15% toabout 40% by weight, the surfactant solution is further comprised ofadducts of from about 2 to about 30 moles of ethylene glycol, from 0 toabout 5 moles of propylene glycol or a combination thereof with linearfatty alcohols having from about 8 to about 22 carbon atoms or fattyacids having from about 12 to about 22 carbon atoms or alkyl phenolshaving from about 8 to about 15 carbon atoms in the alkyl group or alkylamines having from about 8 to about 22 carbon atoms in the alkyl group;alkyl mono- and oligoglycosides having from about 8 to about 22 carbonatoms in the alkyl group; addition products of castor oil orhydrogenated castor oil and from about 1 to about 15 moles of ethyleneoxide or from about 15 to about 60 moles ethylene oxide; a di- ortri-PEG alkyl phosphate and salts thereof; a wool wax alcohol; acopolymer of polysiloxane and a polyalkyl ether; a polyalkylene glycol;a glycerol carbonate; a cocamidopropyl betaine and an ester quat.